Product Description
Crown CR 64074-005 is a hydraulic back-up ring designed specifically for Crown PTH Series manual pallet jacks. This component is used in the seal assembly of the hydraulic pump unit to support O-rings and U-cup seals, preventing extrusion under load. Constructed of high-density elastomeric polymer, it is included in official Crown factory seal kits for the Later PTH hydraulic unit assembly.
Compatibility: Fits pallet jacks made by Crown, model PTH. SKU: CR 64074-005
Specifications
Part Numbers
| Part Number | CR 64074-005 |
| Manufacturer Part Number | CR 64074-005 |
Material & Construction
| Material | High-Density Elastomeric Polymer |
| Function | Prevents extrusion of O-rings and U-cup seals in hydraulic pump assembly |
Compatibility
| Compatible Equipment | Crown PTH Series Manual Pallet Jacks |
| Application | Hydraulic pump unit seal stack assembly |
Frequently Asked Questions
Q: What is the CR 64074-005 back-up ring used for?
A: The CR 64074-005 is a hydraulic back-up ring that supports and prevents extrusion of O-rings and U-cup seals in the hydraulic pump unit assembly. It is installed in the seal stack of Crown PTH Series manual pallet jacks.
Q: Which Crown pallet jack models use the CR 64074-005 back-up ring?
A: The CR 64074-005 is designed specifically for Crown PTH Series manual pallet jacks. It is included in official Crown factory seal kits for the PTH hydraulic pump unit assembly.
Q: What material is the CR 64074-005 made from?
A: The CR 64074-005 is constructed of high-density elastomeric polymer. This material resists extrusion under pressure and maintains dimensional stability in the high-load environment of a hydraulic pump seal cavity.
Q: Why is a back-up ring necessary in a hydraulic seal assembly?
A: The back-up ring prevents O-rings and U-cup seals from extruding or deforming under hydraulic pressure. Without it, seals can bulge and fail, causing leaks. The CR 64074-005 maintains seal geometry during full-load pump operation.
Q: Is the CR 64074-005 included in Crown seal kits?
A: Yes. The CR 64074-005 is included in official Crown factory seal kits for the PTH hydraulic unit assembly. If you are rebuilding the pump seal stack, this back-up ring must be included in the correct stack order to prevent seal failure.
Q: What symptoms indicate a failed back-up ring?
A: Symptoms of back-up ring failure include hydraulic fluid leaking from the pump unit, reduced lift pressure, or slow lift cycles. These occur because the O-rings and U-cups are no longer properly supported. Replace the entire seal stack including the CR 64074-005.